Internal-combustion engines – Starting device
Reexamination Certificate
1999-09-30
2001-12-04
Dolinar, Andrew M. (Department: 3747)
Internal-combustion engines
Starting device
C290S03800C
Reexamination Certificate
active
06325035
ABSTRACT:
TECHNICAL FIELD
This invention relates generally to a method and apparatus for starting an internal combustion engine and, more particularly, to a method and apparatus for providing a high voltage using the energy stored in a capacitor for starting an engine.
BACKGROUND ART
It has long been a common practice to start internal combustion engines using the energy stored in batteries to drive starter motors, which in turn crank the engine until the engine starts. However, the load placed upon the batteries reduces the life of service of the batteries significantly. A typical battery for starting an engine may only have a useful life of about three years. In addition, the power output of even a good battery may be severely reduced when used under extreme temperature conditions.
Advances have been made in technology regarding capacitors, which are capable of storing electrical energy, but until recently were not capable of storing the amounts of energy needed to start an engine. However, large capacitance capacitors, for example electric double layer capacitors, have been developed which are capable of storing large amounts of electric charge. These capacitors are sometimes known as super capacitors, and are finding use in applications such as in engine starting circuits.
For example, in U.S. Pat. No. 5,157,267, Shirata et al. (Shirata) disclose an apparatus for starting an engine which uses a capacitor in parallel with a starting battery. The battery charges the capacitor through a boost controller, i.e., a DC to DC inverter, to a voltage slightly higher than the battery voltage. For example, for a battery voltage of 12 volts, the capacitor would be charged to 14 volts. The energy stored in the capacitor is then used to start the engine, as the battery continues to charge the capacitor during the start cycle.
Although the apparatus of Shirata uses a capacitor to start an engine, the battery must still continue to work under load to maintain a charge on the capacitor. Therefore, the battery must still be subjected to the stresses of continual quick-draining charge-discharge cycles, thus shortening the useful life of the battery. It would be desirable to provide a starting system for an engine which did not subject the battery to constant discharging and charging during the starting process.
In addition, it may be desired to provide a voltage for starting an engine that is much higher than a battery is capable of providing. For example, a large engine may employ multiple starters in the starting system. These starters are typically connected in parallel to accept a constant voltage, e.g., 36 volts, from a battery source. However, the current requirements for multiple starters in parallel is tremendous, e.g., 3,000 amps. It may be desired to connect the starters in series to maintain a relatively low current drain, e.g., 1,000 amps. Components, as well as the wiring, in the starting system could be used at lower ratings and dimensions. The starters connected in series, however, would require a higher voltage, e.g., about 100 volts. A capacitor charged over a long period of time by a low voltage battery, e.g., one or more batteries providing 36 volts, through an inverter, could store a charge in a capacitor at 100 volts to be used to drive the starters as needed.
The present invention is directed to overcome one or more of the problems set forth above.
DISCLOSURE OF THE INVENTION
In one aspect of the present invention a method for starting an internal combustion engine using energy stored in a capacitor is disclosed. The method includes the steps of providing energy at a low voltage from at least one battery to an inverter, boosting the energy at the low voltage to energy at a high voltage, delivering the energy at the high voltage to a capacitor, removing the low voltage source from the inverter, and delivering the energy at the high voltage from the capacitor to at least one starter motor to responsively start the engine.
In another aspect of the present invention an apparatus for starting an internal combustion engine using energy stored in a capacitor is disclosed. The apparatus includes at least one battery for providing energy at a low voltage, an inverter for receiving the energy at the low voltage and producing energy at a high voltage, a capacitor for receiving and storing the energy at the high voltage, means for removing the low voltage source from the inverter, and at least one starter motor adapted to receive the energy at the high voltage from the capacitor and responsively start the engine.
REFERENCES:
patent: 2115671 (1938-04-01), Pfister
patent: 5146095 (1992-09-01), Tsuchiya et al.
patent: 5157267 (1992-10-01), Shirata et al.
patent: 5207194 (1993-05-01), Clerici
patent: 5260637 (1993-11-01), Pizzi
patent: 5563454 (1996-10-01), Araki et al.
patent: 5642696 (1997-07-01), Matsui
patent: 5818115 (1998-10-01), Nagao
Derwent abstract for invention disclosure SU 878992, Pogorelyi et al, Nov. 10, 1981.
Codina George
Richards Thomas J.
Caterpillar Inc.
Dolinar Andrew M.
Lundquist Steve D.
LandOfFree
Method and apparatus for starting an engine using capacitor... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method and apparatus for starting an engine using capacitor..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method and apparatus for starting an engine using capacitor... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2575622